Powertrain Control Module (PCM)

P0627-FUEL PUMP CONTROL CIRCUIT





For a complete wiring diagram, consult the Wiring Information.

- When Monitored:
With the ignition on. Battery voltage greater than 10.4 Volts and the ASD sense switch is on.

- Set Condition:
Actual Fuel Pump state is not equal to desired state. One Trip Fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition Test

2. (K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO VOLTAGE




1. Turn the ignition off.
2. Disconnect the C3 PCM harness connector.
3. Disconnect the C2 TIPM harness connector.
4. Ignition on, engine not running.
5. Measure the voltage on the (K31) Fuel Pump Control circuit at the C2 TIPM harness connector.

Does the voltmeter indicate voltage present?

Yes

- Repair the short to voltage in the (K31) Fuel Pump Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 3

3. (K31) FUEL PUMP CONTROL CIRCUIT OPEN




1. Turn the ignition off.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install PCM Pinout Box 8815 to perform diagnosis.

2. Measure the resistance of the (K31) Fuel Pump Control circuit from the C2 TIPM harness connector to the appropriate terminal of PCM Pinout Box 8815.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the open in the (K31) Fuel Pump Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. (K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (K31) Fuel Pump Control circuit in the TIPM C2 harness connector.

Is the resistance below 100 Ohms?

Yes

- Repair the short to ground in the (K31) Fuel Pump Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 5

5. FUEL PUMP CONTROL OPERATION FROM THE PCM




1. Turn the ignition off.
2. Connect the C3 PCM harness connector.
3. Ignition on, engine not running.
4. With a 12-volt test light connected to ground, probe the (K31) Fuel Pump Control circuit in the TIPM C2 harness connector.
5. Using the scan tool in the PCM, actuate the Fuel Pump.

NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery.

Does the test light illuminate accordingly during the actuation?

Yes

- NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage or terminal push out. Repair as necessary.
If OK, replace the TIPM.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 6

6. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Pump Module and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Fuel Pump and Control Module connectors.
4. Search for any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test